As in saving the changes made to the video once it has been upscaled? All 'upscaling' software/hardware actually does is increase the size of the picture and apply some fancy filters to try and make it look better. To do what you want you'd have to extract the video from the DVD, upscale it and then re-encode it back again.
But why? It's a big increase in file size for something a media player can do on the fly.